W-220 Networking. February 10, 2003Riad S. Twal2 Why create a network Share limited resources Share limited resources Files Printers Scanner Communication

W-220

Networking Networking

February 10, 2003 Riad S. Twal 2

Why create a networkWhy create a network

Share limited resourcesShare limited resources Files Printers Scanner

CommunicationCommunication Internet / Intranet

Email WWW FTP


Types of networksTypes of networks

Peer to Peer (P2P)Peer to Peer (P2P) No centralized control High level of management for security

Client / ServerClient / Server Centralized control Security easily managed


Practical concernsPractical concerns

Cable routingCable routing Server locationServer location Network switch locationNetwork switch location Future expansionFuture expansion


How PC’s are organized…How PC’s are organized…

ClientClient Microsoft Netware

ServiceService File and Printer Sharing

for Microsoft Networking QoS Packet Scheduler SAP Agent

ProtocolProtocol TCP/IP AppleTalk NetBEUI NWLink IPX/SPX


How PC’s are organized…How PC’s are organized…

Client log onClient log on Directly to the machine Common with WinNT, Win2000, WinXP Usually for administrative access to the ‘box’ Can be used for multiple users on one ‘box’ Account on the ‘box’ (local machine)

Network log onNetwork log on Network account, log on to the network Common with WinNT, Win2000, WinXP Used for ‘user’ access to the ‘box’ and the network Account on the network (on the main server)


ProtocolsProtocols TCP/IPTCP/IP - TCP and IP were developed by a Department of

Defense (DOD) research project to connect a number different networks designed by different vendors into a network of networks (the "Internet") http://www.yale.edu/pclt/COMM/TCPIP.HTM

AppleTalkAppleTalk – protocol suite to implement file transfer, printer sharing, and mail service among Apple systems using the LocalTalk interface built into Apple hardware http://www.protocols.com/pbook/appletalk.htm

IPX/SPXIPX/SPX - Internetwork Packet Exchange / Sequenced Packet Exchange, created for use with the Novell NetWare network operating system http://www.protocols.com/pbook/novel.htm


Resources…Resources…

Protocol Directory - http://www.protocols.com/protoc.shtml

Computer Networking http://compnetworking.about.com/cs/basicnetworking/

Network SecurityNetwork Security


Computer Security: Computer Security:

Process of preventing and detecting Process of preventing and detecting unauthorized use of your computerunauthorized use of your computer Prevention measures help stop unauthorized

users (aka "intruders") from accessing your computer system

Detection measures helps determine whether or not: attempted to break into your system if they were successful what they may have done.


Why should I care?Why should I care?

Banking / investing e-Mail Class Rosters Class Gradebook Faculty memo’s


Why my computer?Why my computer?

Random intrudersRandom intruders Hackers looking for a system from which to launch an

attack on another system Direct IntrudersDirect Intruders

Someone looking for private information that you have Credit card info Banking info Gradebooks Faculty / staff / school district memo’s (not

intended for student viewing) Lesson plan files / course delivery material


How easy is it to break into my How easy is it to break into my computer?computer?

“Holes” in any security system are unavoidable (at least when humans are at the controls)

OS and Applications both have ‘Holes’ in security

“Patches” for OS and Applications are constantly being developed They are available via the Windows Update website, or

from the software manufacturers website (ie. Adobe, Macromedia,…)

‘Patches’ do no good if they are not installed and updated.


Internet TechnologyInternet Technology

Broadband Cable Modem DSL

Narowband Analog dialup modem


What does broadband mean?What does broadband mean?

"Broadband" is the general term used to refer to high-speed network connections. DSL (Digital Subscriber Line) Cable Modem Ethernet connection Generally anything over 1Mbps


What is DSL?What is DSL?

Digital Subscriber Line (DSL) Dedicated bandwidth between your location

and the Internet Service Provider (ISP) No guarantee of bandwidth from provider to

the rest of the Internet


What is cable modem?What is cable modem? A cable modem allows a single computer (or network of

computers) to connect to the Internet via the cable TV network. The cable modem usually has an Ethernet LAN connection to the

computer, and is capable of speeds in excess of 5 Mbps Typical speeds tend to be lower than the maximum

entire neighborhoods are turned into LANs which share the same bandwidth

shared-medium topology means that cable modem users may experience somewhat slower network access during periods of peak demand


Broadband vs. dial-up serviceBroadband vs. dial-up service

Dial-up Internet servicesDial-up Internet services "dial-on-demand" service your computer only connects to the Internet when it has

something to send, such as email or a request to load a web page. Once there is no more data to be sent, or after a certain amount of idle time, the computer disconnects the call

modem IP addresses are dynamically assigned, your computer is usually assigned a different IP address on each call.

Broadband servicesBroadband services "always-on" services There is no call setup when your computer has something to

send. The computer is always on the network, ready to send or receive data through its network interface card (NIC). Since the connection is always up, your computer’s IP address will change less frequently (if at all), thus making it more of a fixed target for attack


How do I secure my computer?How do I secure my computer?

When not in use, TURN IT OFF!!! Someone walking by would have to turn it on

before anything could be done Secure the location

Best physical security is behind a dead-bolt Secure the Network Connection

If you are not utilizing network resources, don’t be on the network


How do I secure my computer?How do I secure my computer?

Secure the Network Connection If you are utilizing network resources, don’t share

unnecessary files Sharing the “My Documents” folder automatically

shares all sub-folders as well… Use a Firewall to ‘hide’ your computer

Software Hardware


Practical implications…Practical implications…

We are living in the information age. Information has power (like money use to have), and others will want to have access to that power. While cooperation and sharing is necessary, it is not necessary to share all information with everyone.


Resources…Resources…

NETg@IU Tutorials – Networking Tech. Network Security http://www.indiana.edu/~netg/

CERT/CC – Carnegie Mellon University http://www.cert.org/tech_tips/home_networks.html

Internet Security Alliance http://www.isalliance.org/

Network Control PanelNetwork Control Panel


Controls to look for…Controls to look for…

Machine identification Network identification NIC configuration TCP/IP properties DNS properties File Sharing access


Where are the control panels …Where are the control panels …

Windows 98Windows 98 Start, Settings, Control

Panel, Network Control Panel

OrOr Right click on Network

Neighborhood, Properties

Windows 2000Windows 2000 Start, Settings, Network

and Dial-up Connections, New Connections

OrOr Right click on My

Network Places, Properties

Right click on My Computer, Properties for Network ID


Windows 98…Windows 98…

Clients, Adapters, and Protocols have their own icons

Primary Network Logon: Client for Network Machine

Sharing



Computer name – machine name on the network

Workgroup – where the machine operates

Computer description – unique computer description, allows others to determine what might be shared by the machine



Shared level access High user maintenance Individual passwords

given to each share

User level access Users granted access

based upon participation in the network (users picked from a network list)



Properties for Client for Microsoft Network Determine which domain

to log on to



Properties for Ethernet Adapter Advanced properties



Properties for TCP/IP settings DHCP vs. Static IP DNS WINS



Clients, Services, and Protocols have their own icons

NIC configuration Sharing



NIC Advanced Properties Device drivers…



TCP/IP Properties This has been

streamlined from the Win98 interface

Advanced tab ‘hides’ controls that were overwhelming in Win98



IP, DNS, WINS, and Advanced Options

Win98 has these controls plus TCP/IP Bindings and other low level controls in one window (7 options in total)


Windows 2000Windows 2000

The name of the computer is within the System Properties of Windows 2000.

Windows 98 has the computer name within the network control panel.


Windows 2000Windows 2000

Computer name must be unique on the network

Workgroup A workgroup is a logical

collection of computers that share resources

Domain Same as workgroup;

however there is one single server responsible for managing security


Windows XPWindows XP

Network Control Panel



LAN Properties



TCP / IP Properties



Computer Name Defined within System

Properties Right click on ‘my

computer’ Or Control Panel,

system properties


Useful DOS Commands…Useful DOS Commands…

Windows 98 winipcfgwinipcfg Windows 2000 ipconfigipconfig Windows XP ipconfigipconfig

ipconfig/all ipconfig/all



ipconfigipconfig



Ipconfig/allIpconfig/all



Ipconfig – IUB VPNIpconfig – IUB VPN



IpconfigIpconfig